1. Field of the Invention
The invention relates to a novel Aspergillus species, cyclic dimeric dipeptide derivatives which are biosynthetic products thereof and are useful as Substance P antagonists and therefore as analgesic and/or antiinflammatory agents, and to a process for preparation of the biosynthetic products.
2. Information Disclosure Statement
Springer et al. (Tetrahedron Letters No. 28, pp. 2403-2406, 1977) describes ditryptophenaline having the structural formula ##STR1## as a secondary metabolite of Aspergillus flavus "which possesses neither significant toxic (LD.sub.50 &gt;200 mg/kg) nor antibiotic properties".
Ditryptophenaline has the S-configuration at each of the four carbon atoms identified in the foregoing structural formula as "2" and "10" and as shown by the inventors below has only weak potency as an antagonist of Substance P. As also shown below the invention involves the remarkable discovery that a novel microorganism of the same genus produces by a novel process novel compounds having opposite configuration at the corresponding four carbon atoms and lacking methyl at each of the two nitrogen atoms identified in the foregoing structural formula as "6" and that the novel compounds are potent antagonists of Substance P.